How to make objects appear when I want to see without clicking 'Disable/ object in render'
Keyframes can be added for the visibility settings. Select the object and open the Object tab. In the Visibility panel you can adjust the settings and insert a keyframe either through the context menu or by pressing I.

For your specific problem, you could insert a keyframe at frame 0 with Show in Viewports and Show in Render disabled, then a keyframe at frame 100 with Show in Viewports and Show in Render enabled, followed by a keyframe at 201 with both disabled again.